Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - mathieu

Pages: [1] 2 3 4
General Discussion / Re: Great Divide Northbound Questions
« on: January 18, 2015, 11:17:50 am »
I wouldn't start before half of May. In the north of New Mexico the route goes over 10,000 ft (Polvedera Mesa), over 11,000 ft (Brazos Ridge) and almost to 12,000 ft in southern Colorado (Indiana Pass). You can bypass each on pavement, but it would rob a lot of the route's main beauties. Also many passes in Montana and British Columbia don't clear before mid-June.

From reading many blogs and my own experience, I sketched a chart showing the time windows for going S-to-N and N-to-S in . Of course this is not rocket science.

Routes / Re: Great Divide Rooseville, MT to Helena, MT
« on: August 30, 2014, 09:01:10 am »
Carla, it's an indulgence to go back to the maps and refresh fond memories of those towns and trails of the Great Divide route.
I went through all maps and added all paved sections on the main route longer than 5 miles. I came to a surprising total of 673 miles, i.e close to 25% of the total route!
That old estimate of 5-10% on pavement (also in Wikipedia) is wide off the mark.

Routes / Re: Great Divide Rooseville, MT to Helena, MT
« on: August 29, 2014, 06:44:51 pm »
Adventure Cycling clearly has an unrealistic view of the percentage paved, both for the whole GD route and for this particular section from Roosville to Helena.
In this section roughly 25%, about 90 miles in a total of 370 miles, is paved. The detailing by Iowagriz is also what I remember.
For the total route it is more likely between 10-20%.

I recommend to delay the start, if possible, to mid-May for more agreable overall temperatures.

Flying to Washington-Dulles airport, I rented a large car (small minivan) to transport my boxed bike to a hotel in Williamsburg. A few days later I returned the car to Dulles, took a shuttle to Washington-DC and the afternoon train from Union Station to Williamsburg. This eliminates hauling an unwieldy box and other bags in shuttles and trains. It even allowed a few hours of carefree sightseeing in Washington. Returning a rented car was much less expensive than dropping it in Williamsburg.

Routes / Re: The Great Divide - question
« on: July 29, 2014, 03:34:18 pm »
Depends on how fast you go. Have a look at the chart in . If you can do the route in 1 month (i.e. about 100 mi/day), you may get to the US-Mex border, but if you need 2 months probably not. But this is not rocket science; every year is different.

Routes / Re: Geronimo Trail
« on: June 30, 2014, 07:53:58 pm »

Your start is 4 days before the Grand Depart of the 2014 Tour Divide race from Banff. Even at 100 miles/day, you will probably be overtaken after 7 days by the frontrunners. On you'll find the latest info about snowpack. I saw a cryptical post recently from Matthew Lee himself. He has eyes and ears everywhere on the GD. Follow that link!

General Discussion / Re: Tour Divide Race 2014!
« on: May 09, 2014, 07:28:05 pm »
There are 40 odd pages about TD 2014 waiting for you to read at

Gear Talk / Re: Making wheels stronger with a mixed spoke pattern.
« on: April 21, 2014, 03:58:53 pm »
In the end, for touring use a conservatively designed wheel built by a good wheel builder.  For most touring applications you should not use radial spoking.  Don't use low spoke count wheels, do use a good brand of spokes in a conservative pattern that doesn't require a tensiometer to build.  Use strong rims.  Make sure they're in good repair before starting your tour.

In June, about 120 racers will start for another edition of the Tour Divide race, 2700 miles from Banff-Canada to the US/Mex border. I guess only a few of them will have wheels that fit your recommendation. All of them will have loads that are substantially less than most tourers, probably between 15 and 30 lbs, but their pace is surely much faster and the dirt roads are much rougher. About one-third of them uses rigid forks. I guess for all of them the dynamic  impact on the wheels is much harder than for touring, whatever the load. The race rules prescribe that in case of a mechanical defect, the racer has to go back to a commercial bike shop; no private assistance or forward movement along the GD route is allowed. From the past editions, I do not remember any wheel defect. If it were a serious risk of modern MTB wheels, it would have shown.

What I want to say: there is nothing wrong with being conservative in chosing wheels, but you should be aware that your bike is probably heavier then needed!

Gear Talk / Re: 11-32 vs 11-34
« on: April 21, 2014, 12:05:30 pm »
Sorry for the odd grade measure (yet Wikipedia puts Angle first in Nomenclature ).
Anyhow, it sparked off several interesting topical memories.

Gear Talk / Re: 11-32 vs 11-34
« on: April 21, 2014, 08:54:36 am »
Slopes of  8 degrees is about the maximum you will see on the TransAm.
I think you'll find a lot of people who would dispute that.

John, there are probably few people who are more knowledgeable about the TransAm route than you, so I reverently give way. Still I tried to remember where those wickedly steep slopes occurred. Maybe in Kentucky, where the adrenalin from the many dogs in ambush drove me over the hills?

Did your remark take into account that I mentioned a slope of 8 degrees? More often slopes are expressed as the ratio of rise over run, which for an angle of 8 degrees amounts to a grade of 14%?

Gear Talk / Re: 11-32 vs 11-34
« on: April 18, 2014, 03:11:09 pm »
If you have to ask this question, the best advice is: take 11-34.
As others have said, the difference between 32 and 34 is about half a gear change or -6% in speed at the same cadence. This doesn't sound much, but feels big in the lowest gear.

If you ride at 20 mph, the kinetic energy of your bike and body is about a factor of 20 higher than the energy input from one pedal rotation. If you stop pedalling for a moment the kinetic energy keeps you moving, speed drops slowly and as air resistance drops with the third power of speed, the speed drop is much less than linear with time.
But if you ride uphill with 3 mph, kinetic energy is only about half the energy input from each stroke and gravity weighs linear with speed (at constant gradient). Each pedal stroke has a sense of urgency and speed gets a sawtooth profile because the energy input is only substantial when the crank arms are near horizontal. This 'do-or-die' pounding of the pedals doesn't feel comfortable and doesn't look great.  The more rotations per minute, the smoother and more efficient the pedalling and the less the strain on body (knees) and mind. 

So why doesn't everybody opt for 34t? Well, there is a small weight penalty and the greater efficiency with faster pedalling stops at about 80 rpm. With a 22/32 combination and a 700-32c tires, at 80 rpm you advance about 2.0 m/sec (4.5 mph). At a gradient of 8 degrees, the altitude gain is 0.28 m/sec, which for a weight of 80 kg for rider+bike takes 220W (proportionally more if you are heavier or carrying an additional load). There are not many recreational cyclists around who can produce 220W power in steady-state, say over 20 minutes. Many will reach their limit at 175W steady power output. But those who can produce more power, are lighter or cycle lesser gradients, don't need 34t.

Slopes of  8 degrees is about the maximum you will see on the TransAm. Not in the Appalachians, but in the Ozarks. The Rockies and the Cascades are also less steep.

Gear Talk / Re: Advice on a Bicycle for Trip to France
« on: April 11, 2014, 06:43:22 am »

If I weren't to take the Bike Friday, it would mean purchasing a new bike. My dad always talks about getting a "real bike", however he is referring to a road bike, and I'd be shopping for a touring bike. We only have so much money and so much room in our shed, so for me to buy a pure touring bike for my trip would be a stretch. More practically, the touring bike I purchased could also double as something my dad and I could take out on rides for fun/exercise.

I'd appreciate any feedback on my situation! Should I stick with the Bike Friday? Should I investigate a new bike?

I would seriously consider to make the Cannondale fit for travel. It doesn't involve a great deal, because I saw in the specs that the suspension fork has a lockout, which is important in climbs because it is hard to suppress rocking movements in climbing and each compression of the fork  eats a lot of your power.
The main points for adapting the MTB are tires and ways for carrying your gear.

You should replace the knobby tires with tires that have a smooth surface and possibly smaller width. Schwalbe Big Apple 50 mm is an excellent choice. In laboratory tests they easily beat most 28 mm tires in low rolling resistance. Don't let yourself fool into buying 'unpuncturable' tires like Schwalbe Marathon Plus.  They are heavy going. Punctures, if any, are a small price for a nimble ride.

Regarding carrying gear you mentioned a saddle bag. You could add a frame bag. However, the volume of saddle bag and frame bag combined is small compared to the usual rear panniers, so you have to be a minimalist in selecting your gear. If you cannot reduce the volume sufficiently, you need at least a rear rack. Your frame probably has screw eyelets on the saddle tube for mounting a rack. Try if an Old Man Mountain rack which is supported at the bottom by the skewer, doesn't conflict with the disc brake mounts. Or get a Thule rear rack, which fits on all hard tail MTB's. I wouldn't trust it on bumpy dirt roads, but for paved roads it should be fine. You can always fixate it additionally to the screw eyelets in the saddle tube.

Gear Talk / Re: Making wheels stronger with a mixed spoke pattern.
« on: April 04, 2014, 04:35:43 pm »
..... All a large flange hub does is make the spokes shorter.

Yes and no. I don't think shorter spokes is a real advantage, not even in weight. What a larger hub mainly does is that it enables a larger number of spokes. You see them on tandems, where 48 spoke wheels are not unusual. But with a larger diameter flange, the spokes get more under a skewed angle at the rim, which is a recipe for spoke fracture (viz. Rohloff Speedhubs). We now enter the finesses of wheel building.

What I see over a decade or more of wheel building is that commercial wheel sets use less rather than more spokes, higher spoke tension, a tendency towards 0-cross spoke patterns rather than 3-cross or 4-cross, a reinforcement of the points of attachment of the spokes, a reduction of the rim and nave mass where there are no spokes, and a liberty to introduce arty patterns rather than maintaining traditional artisan symmetries. I guess this is all the result of finite-element design calculations that gave much better insight in wheel strength.

Gear Talk / Re: Making wheels stronger with a mixed spoke pattern.
« on: April 02, 2014, 06:57:02 pm »
I cannot add much own insight to the question whether a mixed spoke pattern makes a wheel stronger, but I believe it does. Wheel design has advanced a bit further than Pat Lamb is probably aware of.
For at least 10 years my road bike has a set of Campagnolo Proton wheels. The front wheel, 22 spokes, has a radial (i.e. 0-cross) spoke pattern. The rear wheel has 24 spokes, 12 at each side. It has a radial pattern on the non-drive side and a 1-cross pattern on the drive side. I have used these wheels a lot on fast descents on bad mountain roads, including several via sterrata in Italy. They never needed truing.
Campagnolo Zonda wheels that are now on the market have 21 spokes on the rear, a number which is bound to violate the 'same number of spokes on each side' rule. They have 14 spokes on the drive-side and 7 on the non-drive side ; all radial. The spokes are grouped in 7 groups of 3, a pattern Campa calls Mega-G3.

The Zonda pattern may well be the result of a design where the striking looks was a prime criterion. The Proton wheel design, however, is from a time when optics were not yet a big marketing point and the finite-element calculation software for making wheels lighter and stronger was available for the industry. That's why I believe that the mixed spoke pattern for the rear wheel is a functional design.

Pages: [1] 2 3 4